The Obama administration slapped new visa restrictions Thursday against pro-Russian opponents to the new Ukraine government in Kiev, and cleared the way for upcoming financial sanctions, as the West began punishing Moscow for refusing to withdraw its troops from Ukraine's Crimea region.

WASHINGTON — The Obama administration slapped new visa restrictions Thursday on Russian and other opponents of the new Ukraine government in Kiev and cleared the way for financial sanctions as the West began punishing Moscow for its occupation of Ukraine's Crimea region.

The new restrictions targeted an unspecified and unidentified number of people and entities that the Obama administration accused of threatening Ukraine's sovereignty and territorial borders.

The action was announced in Washington as Secretary of State John Kerry headed into a meeting in Rome with Russian Foreign Minister Sergey Lavrov. A U.S. official said Kerry urged the Russian government to talk directly to the Ukrainians and pressed for Russia to allow international monitors into Crimea and eastern Ukraine.

The anticipated financial sanctions will penalize "those who are most directly involved in destabilizing Ukraine, including the military intervention in Crimea, and does not preclude further steps should the situation deteriorate," the White House said in a statement. U.S. officials said Russian government officials and entities could be among those sanctioned, though President Vladimir Putin is unlikely to be targeted directly.

The penalties will deepen significantly if Russia presses into areas of eastern Ukraine, senior administration officials said, adding that there is currently no indication Moscow will take that step. The officials also indicated that the penalties could be ratcheted down if Russia pulls back its troops in Crimea and recognizes Ukraine's new government.

"We call on Russia to take the opportunity before it to resolve this crisis through direct and immediate dialogue with the government of Ukraine," the White House statement read.

A senior administration official said the new restrictions are aimed at Russians and Ukrainians in the strategic Crimea region. Crimea is a peninsula that hosts a major Russian navy base and is historically and culturally a Russian stronghold. The official was not authorized to speak publicly about restrictions that had not been announced and spoke on condition of anonymity.

Local government officials in Crimea are now seeking to separate from Ukraine and on Thursday set a March 16 date for a referendum vote on whether the region should become part of Russia.

U.S. officials quickly challenged the legitimacy of the referendum, saying any decisions on Crimea's future that do not involve the government in Kiev would violate international law. The officials also said they believed Russia has had a role in orchestrating the referendum.

The referendum did not affect the timing of Thursday's sanctions announcement, according to the officials, who insisted on anonymity because they were not authorized to discuss the situation in Ukraine by name.

Ukraine's unrest peaked in February, after months of pro-Western protests seeking the overthrow of President Viktor Yanukovych in anger over economic woes and corruption. Yanukovych, who is pro-Russian, fled for protection to a location just outside of Moscow, and Putin sent troops into Crimea in a show of force against the upstart government in Kiev.

The visa bans will be imposed immediately and come in addition to an earlier State Department decision to deny U.S. entry to those involved in human rights abuses related to political oppression in Ukraine. Officials would not say whether Yanukovych was a target of the visa ban or the sanctions.

The sanctions plan, outlined in an executive order, lays the legal groundwork for the Treasury Department to impose financial penalties on offenders. The aim is clearly to punish the separatist movement in Crimea as well as Russia for its decision to send military forces there.